CVE-2010-3448 in Linux
Summary
by MITRE
drivers/platform/x86/thinkpad_acpi.c in the Linux kernel before 2.6.34 on ThinkPad devices, when the X.Org X server is used, does not properly restrict access to the video output control state, which allows local users to cause a denial of service (system hang) via a (1) read or (2) write operation.
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Analysis
by VulDB Data Team • 10/07/2021
The vulnerability described in CVE-2010-3448 resides within the thinkpad_acpi driver component of the Linux kernel version 2.6.34 and earlier, specifically affecting ThinkPad devices that utilize the X.Org X server for graphics rendering. This flaw represents a critical access control issue that undermines the security model of the kernel's hardware abstraction layer, particularly concerning video output control state management. The vulnerability stems from insufficient permission checks within the driver's implementation, creating a path for unauthorized manipulation of hardware control registers that govern display functionality.
The technical implementation of this vulnerability occurs through improper access restriction mechanisms within the thinkpad_acpi.c file, which fails to validate user privileges before allowing operations on video output control state variables. When local users execute either read or write operations against these unprotected control registers, the system becomes vulnerable to denial of service conditions that can result in complete system hangs. This occurs because the driver does not properly validate whether the requesting process has appropriate authorization to modify display output states, effectively allowing any local user to manipulate hardware-level graphics controls that should be restricted to privileged system components or root-level processes.
The operational impact of this vulnerability extends beyond simple denial of service, as it represents a fundamental breakdown in the kernel's privilege separation model for hardware access. Attackers can exploit this weakness to disrupt system functionality by triggering invalid state transitions in the video output control mechanisms, potentially causing the entire system to become unresponsive. The vulnerability affects systems where the X.Org X server is actively running, making it particularly relevant in desktop environments where graphical user interfaces are prevalent. This flaw demonstrates a classic case of insufficient input validation and access control enforcement, which aligns with CWE-284 access control weaknesses and represents a significant risk to system availability and stability.
Mitigation strategies for this vulnerability require immediate kernel updates to version 2.6.34 or later, where the access control restrictions have been properly implemented within the thinkpad_acpi driver. System administrators should also consider implementing additional security measures such as restricting local user privileges and monitoring for unauthorized access attempts to video output control registers. The vulnerability highlights the importance of proper privilege enforcement in kernel drivers, particularly those managing hardware-level graphics controls, and serves as a reminder of the critical need for robust access control mechanisms in operating system components. Organizations should prioritize patch management to address this vulnerability and implement monitoring procedures to detect potential exploitation attempts. This flaw demonstrates how seemingly minor access control oversights in kernel drivers can create significant system stability risks and represents a classic example of how insufficient privilege validation can lead to system-level denial of service conditions.